A randomized controlled trial of Oregon's comprehensive preventive intervention is proposed. The project will extend a successful collaboration between state agencies and Oregon Research Institute that for 3 years has measured tobacco control practices, individual risk/protective factors, the prevalence of tobacco use, and other healthy/harmful behaviors of adolescents in a cluster sample of 1/3 of Oregon middle and high schools. Oregon's Tobacco Prevention and Education Program (TPEP) is a tobacco tax-funded intervention that supports school districts and their communities in implementing a prevention program. The components of the program include policies against tobacco use, school-based curricula, youth anti-tobacco activities, family communications about tobacco, and access reduction efforts. Using a group-randomized design, with a waitlist/ multiple design feature, 36 school districts, not previously receiving tobacco program funding, will be randomly assigned either to intervention 1, 3, or 4 years into the project or to a no-intervention control condition. Annual assessments of all 8th and 11th graders have been obtained for the past 3 years and will continue for the 5 years of this project. Data on implementation and mediators of program effects will be obtained from students, teachers, principals, prevention coordinators, access purchase surveys, and archival records from schools, police, and city councils. The primary aim of the study is to conduct a true experimental field trial of a state program. In doing so, it will provide evidence about the implementation and effectiveness of comprehensive tobacco prevention programs when administered by the state and delivered by non-research personnel. It is thus both an effectiveness and a dissemination trial. Given the comprehensive nature of our survey instrument, we will also be able to test whether a prevention program targeting tobacco use has an impact on young people's engagement in other problem behaviors. Finally, the proposed research will permit continuing our analyses of the relationship of adolescent smoking to other healthy and harmful behaviors and of the role played by social context factors in influencing the development of these behaviors.